This invention relates to movable support assemblies which provide for the extension and retraction of storage elements between open and closed positions. More particularly this invention relates to improved and balanced support assemblies which provide for the opening and closing inclinations of counterpoised storage elements.
1. Background--Description of Prior Art
In the prior art various slides, rollers, and complex linkage assemblies support storage shelves, drawers and container elements. A problem which this invention seeks to overcome is best explained in connection with drawer support assemblies although it is to be understood that this invention has many other and different support applications. In existing drawer assemblies accessability and visibility within the drawer requires extension of the drawer beyond the anterior frame supports. Extended drawer positions produce cantilevered moment forces distributed between the anterior and posterior bearings in opposing directions. Positioning the drawer over the anterior supports balances the drawer center of mass over the anterior support frame, partially opened. Closed drawer positions produce vertical loads in the same direction distributed between the anterior and posterior bearings. Drawer movement between extended, balanced and closed drawer positions present complex problems with the changing bearing requirements.
Drawer bearing forces in various drawer positions present problems of unknown ergonomic force requirements needed for movement. The drawer distributes varied loads between opposite sides of the drawer support assembly. Drawer movement between parallel supporting assemblies requires forces which enguage motion on opposing sides simultaneously. Principle motion may occur independently along one side in response to unevenly distributed loads and forces. Jamming from unevenly distributed loads and operator forces produces a problem with predicting the ergonomic forces required for controlling parallel movement.
Various complex display rack support assemblies provide for tilted drawer positions. Movement between tilted and horizontal positions requires operator support of the extended portion of the drawer. The control of jamming restrictions is divided between the operator and the plural posterior drawer supports. The parallel ergonomic requirements of tilting manipulations present ergonomic problems detering the populus use of tiltable assemblies.
In the prior art, a Watt's type double lever four bar linkage provides prior art formula assisting in the technical application of the invention.
2. Objects and Advantages
There is provided, in accordance with the present invention, restrained inclination of supported elements between open and closed positions provided by parallel proportional four bar linkage supports. It is the general object of this invention to provide a joint solution to the support of drawers and tiltable assemblies without complex ergonomic problems. The proportional linkages balance the supporting movement through opening and closing inclinations by counterpoising the weight of the drawer within the linkages motion.
A objective feature demonstrated by this invention envolves to use of gravitational forces acting on storage elements weight or mass. Storage element inclination provides storage exposure without cantilever of the drawer center mass beyond the anterior supports.
Advantages of this invention generally follow the united features of parallel proportional support linkages. Providing drawer support through pivotal linkage bearing supports provides a simple bearing relationship with the frame. A simple pivotal support assembly enables a consistant range of motion and ease of repeated storage. Restrained drawer inclinations employ the rotational drawer mass and reduces the independent motion and jamming restrictions as compared with existing assemblies.
A advantage demonstrated by the invention disclosure provides substantially interchangable components promoting varied applications. Other objects and advantages of the invention will be apparent from the following description and use by construction.